Thread-cutting die



0. 5. LEE THREAD CUTTING DIE File ii Sebt. fl). 1923 "Hill":

Illllllll'! A ril 28, 1925.

Patented Apr. 28, 1925.

UNITED STATES 1,535,728 PATENT OFFICE.

o'rran s. LEE, on cnroaero, imirnoraassisnon 'ro THE NYE root & aonrnn WORKS, OF CHICAGO, ILLINOIS A CORPORATION OF ILLINOIS.

rnnnanonrrxne DIE.

Application filed September 10, 1923. Serial N'o. 661,878,

To all whom it may concern:

Be it known that I, O'r'raa S; Lnn, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in lhread-Cutting Dies, of which the following is a specification;

My invention relates, more particularly to dies of the type comprising a body equipped with a plurality of thread-cutting segments disposed generally in a radial direction about the central opening in the body.

as dies of this character have hitherto been constructedthey are formed of a. body of cast iron the metal of which is cast, in the manufacturing of the dies, about the die segments of tempered steel, the segments becoming welded to the body in this opera tion. So constructing dies presents many disadvantages among which are that the cast iron body of the die is relatively fragile often becoming broken in the use of the die; the die segments which it is desired, and which it is necessary, when the teeth are cut to produce backed off dies, be spaced apart in predetermined positions, oftentimes become displaced in the molding operation and consequently in the completed die and thus render the die defective. Furthermore, the carbon-content in the steel segments becomes greatly reduced, by being,

burned out in the subjection of the segments to the molten iron poured about them in the forming of the die body about the segments, requiring restoration of the carbon content, with consequent great expense.

My object is to provide for the more economical production of, dies of the general character above stated, and to produce dies of such character that they will not be liable to break in use and the proper positioning of the segments relative to each other will be insured; and other objects as will be manifest from the following description.

Referring to the accompanying drawings: Figure 1 is a face view of the parts forming my improved die showing them in as-- sembled relation but before they have been permanently secured together. Figure 2 is a similar view of the completed die. Figure 3 is a perspective view of one of the similar sections of which the body of the die is formed. Figure 4 is asection taken at the line t on Flg. 1 and vlewed n the direction of the arrow; and Figure 5, a

section taken at the line 5 on Fig. 2 and viewed in the direction of the arrow.

Inaccordance with my invention I pre-,

trally apertured, as represented at 10, and

slotted, as indicated at 11, these slots being preferably disposed as shown, and arranged generally to radiate from the center of the plate-portion, the walls of these slots being chamfered at theouter surface-of the plateportion, as represented at 12.

The sections 6 and 7, in the constructing of the die, are assembled with each other to the position shown, by virtue of which a hollow frame-like body is produced, the flanges 8 forming the four side walls of the hollow body, and the plate portions 9 the opposite face portions of the body, it being understood that the slots 11 in one of these face-forming plates are in direct alignment with the corresponding slots in the other of these plate portions, adapting them to receive, and properly position therein, the die segments represented at 13, the

welding, for example by the electric are welding process, the joints therebetween, to form a rigid frame like hollow body. The die segments 13 are secured in the body, in the position shown, in any suitable way, preferably by welding, as, for example, by the electric arc-welding process, the oints between the segments and the walls of the slots 11 inwhich they extend, the chamfering of these walls at 12 facilitating the rigid uniting of the segments to the body. The cutting portions of the segments 13 and in dicated atl t, are preferably formed in any suitable manner, as, for example, as now commonly practiced.

From the foregoing it will be noted that a die constructed in accordance with my invention may be manufactured relatively economically; the die is strong and resistant to stresses in use, rendering it unbreakable; theheat to which the segments 13 are subjected in the uniting of the segments with the body is not required to be such that there is any danger of the burning of any of the constituents of the metal of which the segments are formed; and accu ate positioning of the segments relative to each other and to the body, is assured.

lVhile I have illustrated and described a particular construction embodying my invention, and have described a certain particular way of manufacturing the die, I do not wish to be understood as intending to limit it thereto as the die structure may be Variously modified and altered, and the same produced by variations in the method described, without departing from the spirit or my invention.

lVhat I claim as new, and desire to secure by Letters Patent, is:

1. A die comprising a body formed of upper and lower flatwfse opposed portions spaced apart and side-wall portions united with said upper and lower portions and :l'orming therewith a hollow structure, said first-named portions containing aligning apertures and slots opening into said apertures, and die segments located, and secured, in said slots.

2. A die comprising a structure of hol low, box-like formation, composed of sections of U-shape, each consisting of a face portion with side flanges at two oi? its edges and provided in its face portion with an aperture and slots opening into said aperture, said sections being placed together to form the structure with the side flanged portions of one in reverse relation to the side flanged portions of the other and with the central apertures and slots of said sections in registering alignment, and die segments located and secured in the slots.

3. A die comprising a hollow frame-like body presenting an aperture therethrough and containing slots in its opposite face portions opening into said aperture and formed of similar sections secured together and each presenting one of said face portions with flanges extending therefrom, the latter constituting the side walls of said body, and die segments located, and secured, in said slots.

a. A die comprising a hollow frame-like body presenting an aperture therethrough and containing slots in its opposite face portions opening into said aperture and 'fOl'l'l'ltil of similar sections secured together and each presenting one of said it'ace portions with flanges extending therefrom at opposite edges thereof, the flanges on one of said sections extending adjacent the ends oi the other of said flanges at the spaces therebetween, and die segments located, and secured, in said slots.

A die conlprising a sheet iron body formed of upper and lower flatwise opposed plate-like portions spaced apart and side wall portions united with said plate-like portions and forming therewith a hollow structure, said plate-like portions containing aligning apertures and slots opening into said apertures, and die segments located, and secured, in said slots.

OTTAR S. LEE. 

